利用光展量概念之微型投影機光學設計方法與實作

Optical System Design and Development of Pico-Projector Using Etendue Concept

吳欣潔(Hsin-chieh Wu)

指導教授 ： 伍茂仁 ； 孫文信 ； 紀國鐘

國立中央大學/理學院/光電科學研究所/碩士(2012年)

摘要

本論文提出一組微型投影機，其架構利用L型光路結合成像以及非成像系統，而光源及光閥使用色序式的操作，光源使用一組RGBG陣列之發光二極體模組，光閥系統為反射式矽基液晶面板，使用上須搭配偏振分光器；非成像系統由準直鏡，微透鏡陣列積分器以及聚光鏡組成；準直鏡為兩片球面鏡片，為減少受光源的熱影響材料使用玻璃，微透鏡陣列積分器使用兩片相同的雙面同曲率塑膠鏡片，由於使用的偏振分光鏡有聚光鏡功能，便不須在非成像系統中製作聚光鏡，成像系統則使用市面上現有的鏡組。
由於越高收光數值孔徑的準直鏡的光學效率越高，因此設計出數值孔徑值為0.985(sin80°)的準直鏡；而做混光以及調製光型用的透鏡陣列積分器則要搭配偏振分光器上的聚光鏡做設計，最後透鏡陣列出光的數值孔徑便訂在0.574(sin35°)，而製程限制下單片透鏡陣列出光的數值孔徑無法滿足目標值，最後將其設計為一組雙片，而調製光型的部分每塊微透鏡大小設計為SVGA的4 : 3比例(1.225 mm× 0.919 mm)。
設計完成之非成像系統含外殼尺寸為13.1 mm× 11 mm× 11 mm，體積1.6 cc，加上成像系統總尺寸為34 mm× 31 mm× 11 mm，體積11.6 cc，而此系統在LED功耗為1 W時可得約4.0 lm/W的效率。

關鍵字

矽基液晶 ； 微透鏡陣列 ； 非成像系統 ； 微型投影機

並列摘要

In this thesis, an architect of pico-projector using L-shape light path that combines an image system and a non-image system is proposed, and the system is operated in Field-Color-Sequential (FCS) way. A RGBG-array LED is applied as a light source in this system. The liquid crystal on silicon (LCoS) is chosen to be the image display, and it would be accompanied with a polarization beam splitter (PBS) in the pico-projector. There are a collimator, an integrator, and a condenser forming the non-image system. The collimator systems are realized using two sphere-shape lenses, and its material is chosen to be glass to avoid the heat damage induced from LED light sources. The integrator is consisted of two pieces of micro-lens arrays (MLAs), and the PBS is also possessed the function of condenser.
The collimator with a numerical aperture (NA) of as high as 0.985(sin80°) due to the higher optical efficiency of the system is necessary. The NA of MLA of 0.574(sin35°) is set to be larger than the half field of view (HFOV) of the condenser. The MLA of two-element configuration is adopted as considering the molding process constrain. The micro-lens pitch of MLA of 1.225 mm× 0.919 mm is compatible with the panel-size ratio of SVGA.
The size of non-image system is 13.1 mm× 11 mm× 11 mm, and its volume is 1.6 cc. The size of the pico-projector is 34 mm× 31 mm× 11 mm, and the whole volume of projector is 11.6 cc. The efficiency of proposed projector of 4.0 lm/W is demonstrated experimentally under the power consumption of LED light source of 1 W.

並列關鍵字

liquid crystal on silicon ； micro-lens array ； non-image system ； pico-projector

參考文獻

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